Method of burning pulverized fuel



July 31, 1923. I` 1,463,283

H. KRl-:lslNGl-:R

METHOD OF BURNING PULVERIZED FUEL Filed oct. 22 1920 2 sheets-sheet 1 W/TNES'S,

IN V EN TOR.

A TTORNEYS.

July 31, 1923. 1,463,283

H.KRmmNGER METHOD OF BURNING PULVERZED FUEL Fild oet. 22 1920 2 sheets-sheet 2 f f F550 PUMP IN V ENTOR.

BY v A TTORNEYS.

' To all whom t camera:

Patented*duly -I i@ a HENRY KREISINGER; OFPITTS'BURGH, PENNsYLvANm, ksissIeNoR To vcoiinus'iioti .ENGINEERING CORPORATION, A coRPoRA'rmiii or NEW YORK.' f

METHOD or -nuRNiNe PULVERIZRD FUEL.`

v'application' inea october 2z, 1920. .serial Naiiaelio.

Beit known that I, HENRY KnEisiNeiiR,

Y- a citizen of the'United States, residing at f It is the specific object of my invention .to provide means fortreating such ash and refuse during combustion of the fuel 1n such manner as to prevent their forming from above and to permit itlto drop more orA l' less gently toward'the zone in which conibustion thereof takes place. The furnaceis furnace, .diicult if not impossible to remove.

- and fuse together to form a massof. liquid Pittsburgh, in the county of Allegheny and State of'Pe'nnsylvania, have invented Acertain new vand useful Improvements in Methods of Burning Pultierized- Fuel, of which the following is a specification.

This invention relates to the burningoj@- pulverized fuel and particularly to an improved method of treating and disposing of theslag forming ash and refuse.

into a mass of slag in the bottom of the Dueto the intense heat prevailing the precipitated ash and refuse generally melt slag on theiloor of the4 furnace which cannot readilybe removed andwhich, if per- 1 4thetloor. I`propose to overcome these dif# mitted to cool, solidies into a solid cake, which mu's't-lijterally be dug out.

. l am awarcalthat it has heretofore been.

contemplated to overcomethese difficulties by -cooling the precipitating ash and refuse below'slag forming temperature by providing a cooling ione tov wit, by a blanketbf flowing air Ibelow the zone of combustionV and throughy which such products fall Vto culties by mechanical means.

. ylily invention; therefore,-contemplatesfthe 'provision of whatmay be termed awater screen located in an approximately horizontal orA slightlyinclined planeat a point --a--short distance above the Hoor of the fur- ,nace, preferably connected lation of the boiler.M

with the circu- The foregoing, aswell as other objects,l will be'more clearly understood andap'prescription of the accompanying f drawings wherein l have illustratedseveral forms of apparatus suitableor carryingnout my improved process, andvof which Fig. 1 v'saverticalilongitudinalsection ryine f vides a means for controlling the i @admitted through the channel. 1' ciated in connection .with the. following ldefwf.. At variouspoints inthe front wall 1 of the furnace are located the auxiliary air inerating-,means 11 forthese doors may be .provided `if desired. In Figs. 2 and 4 the .'c'onfusion L in the showing.

. suitable for carrying out my invention.

In the showing of Figs. 1 and 2 `the coinlbustion chamber A of the steam generating furnace-illustrated, which is indicated as a whole by the` reference character B, is providedwithany desired or suitableyform of fiiel delivery means or burner C. Une or more th-an one burner may be used and in `the present instance I have illustrated two which are located in the np'perwall of the combustion chamber at a point somewhat to the rear of the vfront wall 1." It will be noted that these burners occupy a vertical position K*as I prefer to introduce the fuel provided with a suitable outlet 2 for the hot vlgasesland other products of combustion which are drawn off under the influence of -ment of water tubes for the generation of steam. v Referring tothe details of the burner it',

might be Well-to point out that the mixture' offuel is introduced through the pipe-@2l the flow of which is aided, if'desired, bymean's of a jet of steam'or air introduced through usedat all, be not at'any time'violentaa'sl desire the fuel after it enters the furnaceto follow the more or less gentleand natural lpath through the zoneof combustion iniarylopenii'igs or channels 6 and 7 through `which additional air may be induced' into the combustion chamber. A damper .8; proysupply chains are not illustrated in order vto avoid t a short distance above arrange-a1.plurality of spaced. tubes v13 the pipe 5;- I prefer that this jet, iffjt 'hecA which "araincliied'slightly from thev rear wall 1s tp the front wall 1. Below the up- `per ends` of the tubes Iand in the front wall of the furnace are provided two ash or Slag removing doors 15.

rlhe following novel arrangement provides a circulation of water through the tubes 13. Extending transversely of the furnace and located in 4the rear wall 1i thereof isan inlet header 16 which communicates with all of the tubes, and 1n the front Wall of the furnace is located, also trans- ,versely of the furnace, an outlet header 17,

connecting with the otherends of the tubes.

Certain of the usual water tubes 3, preferably those-in the outer lower corners, are omitted and are replaced by the pipesl 18 leading to the ends of the `header 16, and

by the pipes 19, connected to the ends of the header 17, thepipes 19 being bent inwardly so as to extend into the upper portion of the combustion chamber.

lin Figure 3 is illustrated a modification in which two or more tubes 19a connect the header 17 with the steam drum, such tubes being located entirely withoutthe furnace. A'suitable connection 21\leads to the header 16 from av source of water supply and la feed pump 20 vis provided in the line. rlihe pipes 18 1n this case, act to p-rotect the apparatus atvtimes when the pump is notgin operation. ln the modification of Fig. 4, theheader 16 is connected as before to a source of sup- `ply and is fed by a pump 20, lwhile a hot water line 22 is connected to the header 17 and leads t0 any desiredr point of use. lin this form, therefore, the water screen is independent of the boiler settingand is used `as a heater in addition to its other functions precipitating ash' and refuse from closing the same.

It will be seen from the foregoing that in all the forms described theash and refuse `which gravitate and .such as are carried along with the flames toward the water screen during the burning of the fuel will either strike and lodge on or pass closely adjacent to the tubes of the water bottom.

Such ash and refuse as lodge on thel lations on tlfetfiibes with the result that it is common for the same to drop od. rlhe de oslt on Ithe floor is composed of the ash an of the material falling from the tubes .and of the drippings, if any, which latter take the form ofsmall particles or nodules.

\. Lacasse melting or coalescing of the deposit into a solid mass of slag because they absorb the radiant heat of the deposit and maintain the temperature of the deposit at a point below that at which fusion or coalescing takes minture of ash and residue of a character which can be easily removed, the deposit being removed in normal operatmn and not allowed to build up to a point where it tained at a pointr preventing appreciable coalescing.

I-have illustrated the water screen as com-v posed of a plurality 'of-spaced tubesbut it will readily be seen -that other means might well be employed. lit is essential only that the cooling surfaces of the water screen be interrupted as with openings or spaces and yet arranged to provide a surface continuous enough to produce the desired results, in other words to provide a fluid cooled medium of sufficient capacity and arrangement to prevent appreciable coalescing of the precipitating ash particles and the deposit thereof.

Low grade fuels normally produce great slagging ypdiiiculties. lt will be apparent that this improved method of treating and disposingof the slag forming ash-and refuse makes it possible to successfully utilize fuels of a grade ordinarily too low for practical purposes. -I l In -all the forms, l cut back the side walls `place and the deposit, therefore, remains a to above thetubes to provide an overhanging shoulder or lip' 211 from which the slag which is formed on the side walls can drop @off either onto or closely adjacent the tubes.

These drippings may be of comparatively large size and some of them may coalesce or partly coalesce, but the heat'absorbed by the screen lis suiicient to `prevent `the formation of any lumps dicult of removal. rllhis is an important feature of my invention Ias the formation of slagen the side walls has heretofore presented very troublesome obstacles in the burning of pulverized fuel.

lit is well known in the pulverized fuel burning art that the temperature in the coinbustion is sufficient to fuse the Irefuse particles of the coal being burned in suspension and these partlcles in the absence of cooling will collect andrun together into a coalesced mass such as previously described. The water screen described herein is a mechanical fluid cooled heat absorbing medium-dependent upon the indirect effect of a Huid ',lhecomparatively cool tubes prevent the \cooling medium as \'water-through which jected to the iniiuence thereof in a manner Y the precipitating particles pas/s or are subto prevent the collection, of'an appreciable mass of coalesced material; and this screen is arranged between the flame and the surface on which lcollection or deposit takes place, so thats cooling zene is created which prevents coalescence of refuse particles passingout of the iiame and o`f the deposit there-l of in the protected space intermediate the w liame andthe recipient surface. It 1w1ll also be observed that this water screencreates a lrelatively cool zone towards lor through which particles of refuse in the combustion zone travel from the flame and which parti'- cles, if not cooled below coalescence .by the screen, would lodge von a refractory or other hotsurface and form 0r collect into a runny or'flowing coalesced mass 0r body, and the .cooling by the fluid cooled means for preventing this is an important aspect of my invention. .v

.. claim: y

l; The process of burning fuel-in a combustion chamber which consists in admitting, ignting and burning the fuel within such chamber, and in creating and maintaining a cooling zone in such chamber, intermediate th'e ame and a recipient defining surface of Asuch chamber, through which -zone refuse particles leaving the flame in regular substantially continuous operation pass toward such surface and which zone is passin operation to a-recipien't. defining surface lof such chamber while the particles are in suspension in the chamber and inalso cooling the deposit thereof in the chamber,` down to Y a consistency at whichl the particles 'will not `run, by the indirect action of a cooling me'- dium. y

3. The method which comprises supplying pulverulent fuel to the interior of a combustion chamber into which combustion supporting airl Hows, substantiallyv completel burning the fuel While 'within said` cham er, and While the gaseous prodpcts of combustion pass from' the-chamber, and in cooling refuse particles passing from the iamefstream during the normal continuous operation toward a'surface of such chamber while the are in vsuspension in the' chamber, bythe e ect of'an indirectly! applied cooling medium,below the coalescing temperature of said particles: l i

4. The processof burning fuel in a comiA aing andbu'ing'the fuel within Such C amber and in cooling refuse particles passing fromlthe fla-mein regular normal operation to a recipient surface defining such chamber, down to a'l consistency at whichthe particles'will not run, whilethey are in susll pension within the chamber, by the cooling effect of water in pipes constituting a screen within Athe chamber.`

5. The process of burning fuel in a com.- bustion chamber wherein the fuel is admitted and subjected tol substantially complete combustion therein, and in which therefuse particles passing from the flame in normal substantially continuous operation are prevented from forming into a body ofy liquid on a surface of such chamberby being suficiently cooled while in suspension vwithin such chamber by' the indirect cooling action of a water-cooled heat absorbing screen lo cated in advance of said surface, toward Which said refuse travels 'from the flame.

6. The' process 'of burning fuel insuspension in. afco'mbustion chamber in which the refuse\p'articles passing from theflame in normal re lar operation toward -a surface of such c amber and depositing thereon,

are cooled below the point lof coalescence by causing such particles during the movement to the place of de osit in the chamber to pass through a coo ing zone created by the absor tion of'heat by the indirect action of la cooling medium, and" in removing deposited material before fthe accumulation thereof cooling. z f

7. The processof burning fuel in a comis suiiicient to defeat a continuance of such` W@ bustion chamber wherein the' fuelis admitted in pulverized form and vsubjectedtofsubstantially complete combustion while in sus- -pension thereinatl a temperature above the ppint. ofthe refuse `,of the fuel, in

fusing which t e refuse particles precipitating out of the flame: in regular operatiom'deposit in'.

an ash-receiving space below the zone of combustion and are cooled in transitl .and

`8. The process of burning fuel in suspension in a combustion chamber wherein the fuel is admitted and subjected to substantially complete combustion therein and the refuse particles precipitating out ofthe -ziame in regular operation are allowed to deposit within the .combustion chamber, in which process -the.precipitating and. precipitated articles are cooled and are maintained coo below-the temperature yat .which which cools to therequisite temperature and:

the ,wi1lfuse, by a heat absorbing medium l bustion chamber which consists in admitting, ;maintains cooledj` to\the requisite tempera- W0 ture, the precipitating and precipitated particles, but which cooling medium, during its cooling, does not mix with'the products of combustion.

9. The process of burning fuel in a, combustion chamber, wherein the fuel is admitted, ignited and substantially completely! burned therein, in which refuse metter pass- Y ing out of the flamestreern directly to aJ place necmeee y below @point et which a, iowing mess thereofcan form on the place of lodgrnent, this being accomplished by cooling and maintaining solid matter cooled, by the indirect atction of a, coolingmedium, below the tempereture of coalescence of the refuse particles. In testimony whereof,- li have hereunto signed my neme.

l HENRY KlltlEllS'lNGlI-ER. 

